The 94 GHz and 35 GHz Cloud Radars
The real-time radar images on these pages are being taken by the 94 GHz radar called Galileo and the 35 GHz radar Copernicus. The two radars are mounted on the ground near the main 25 metre antenna at Chilbolton Observatory. These high frequency radars are especially suited to studying clouds; they are more sensitive than lower frequency radars, but more importantly they are unaffected by ground clutter, that is hills, trees and buildings.
Galileo and Copernicus are located near the main Chilbolton radar, CAMRa, so that the three instruments can measure together. CAMRa (Chilbolton Advanced Meteorological Radar) measures at the much lower frequency of 3 GHz. Researchers can infer the sizes of precipitation particles in the atmosphere by comparing the ratio of reflectivity at the two different frequencies. Both the cloud radars are Dopplerised, which means that scientists can measure the range of speeds at which precipitation particles fall.
Details of the 94 GHz radar Galileo
| Radar type | BISTATIC |
| Frequency | 94.00 GHz |
| Antenna diameter | 0.6 m |
| Peak power | 1.6 kW |
| Pulse width | 0.5 microseconds |
| PRF | 6250 Hz |
| System noise figure | 10dB |
| Maximum range resolution | 60 m |
| Noise at 1km | -36 dBZ |
Details of the 35 GHz radar Copernicus
| Radar type | MONOSTATIC |
| Frequency | 34.960 GHz |
| Antenna diameter | 2.4 m |
| Peak power | 1.7 kW (excluding feed losses) |
| Pulse width | 0.1 - 25 microseconds |
| PRF | 625 Hz - 20 kHz |
| System noise figure | 5 dB (excluding feed losses) |
| Maximum range resolution | 30 m |
| Noise at 1km | -35 dBZ (0.5 microsecond pulse, no integration) |
For more information on the cloud radars take a look at our Facilities page.
